A Canadian mother has told of her shock at discovering her 13-year-old son had been given a school handout instructing him to cook and then inject crystal meth during a drama class.

Delight Greenidge, of Mississauga near Toronto, broke down in tears as she read through the dangerous instructions handed out to her son by a teacher at Erin Mills Middle School.

"I popped a blood vessel," she said. "I was in a state of shock ... I'm thinking this cannot be real."

Greenridge claims the printout – which includes detailed advice for the preparation and injection of methamphetamine, or crystal meth – was given to students in a grade-eight drama class.

"It's mind-boggling," she said. "It could undo a lot of what I taught him because sometimes he would think the things the teacher says are sometimes more important than the things mum says. They do have that influence and impact."

The students were apparently given the dangerous directions after they failed to come up with their own original skits for the class. Greenidge was particularly disgusted by a section in which they were instructed to "act happy" while injecting the deadly drug. Another read: "Give your arms a wipe with alcohol wipes (what I use) or use a wet wipe, this is to prevent any bacteria infection."

The Peel District school board has apologised to Greenidge and expressed its solidarity with her position. "I can't speak to his rationale for doing that," said Carla Pereira, communications manager at Peel District school board. "We share the parents' concerns around that particular assignment."

The board claims that the teacher got the cooking instructions off the internet. The teacher has not been identified and there is no suggestion that they manufacture, use or sell methamphetamine.

Fighting back the tears as she spoke to CBC News, Greenidge said: "To think that all of what I've tried so hard to teach him — good principles, good values, moral character — the things that make you a man, a strong black man, and this is what an educator is giving to my child."